Steam-valve



5Sheets-Sheet 1. D H RICE STEAM VALVE.

(No Model.)

Patented Apr. 3, 1888.

lll l I 3m 'EYRQT.

5 Sheets-Sheet 2.

(No Model.)

D. H. RICE.

STEAM VALVE.

No. 380,661. Patented Apr. 3, l 8.

mum

Wfimaasaa.

(No Model.) 5 Sheets-Sheet '3.

1). RICE. STEAM VALVE.

No. 380,661. Patented Apr. 3, 18.88.-

N. PETERS. Plmlo Lithngmphcn Washingfnn. D c.

(No Model.) 5 Sheets-Sheet 4.

' D. H. RICE.

STEAM VALVE. I No. 380,661. Patented Apr. 3, 1888.

Wiinmms (No Model.) 5 Sheets-Sheet 5.

D. H. RICE. STEAM VALVE.

Nb. 380,661. Patnted Apr. 3, 1888.

UNITED STATES PATENT OEFicE.

DAVID HALL RICE, OF BROOKLINE, ASSIGNOR TO JAMES FERGUSON, OFBRIDGEWATER, MASSACHUSETTS.

'STEAlVhVALVE.

SPECIFICATION forming part of Letters Patent No. 380,661, dated April 3,1888.

Applicaton filed December 12, 1887. Serial No. 257,590. (No model.)

To all whom it may concern.-

Be it known that I, DAVID HALL RICE, of Brookline, in the county ofNorfolk and State of Massachusetts, have invented certain new and usefulImprovements in Steam-Valves, of which the following is a specification.

My invention relates to steam-valves for 10- comotive and other engines;and it consists in certain new and useful constructions and combinationsof the various parts thereof, substantially as hereinafter described andclaimed.

My invention relates to balanced valves for steam-engines, and isillustrated as being applied to the type shown and described in theLetters Patent N 0. 385,571, granted to James Ferguson February 9, 1886,although it may be applied to other types.

In the drawings, Figure l is atop plan view of a steam-chest with thetop removed, showing the valve and its cylinder with my improvementapplied thereto. Fig. 2 is a transverse vertical section of the same onthe dotted line X X. Fig. 3 is alongitudinal vertical section of thesame on the dotted line WV W. Fig. 4 is a top plan view of thevalve-cylinder, with a modification of my relief-valve shown in Fig. 1.Fig. 5 is a transverse vertical sec tion of the same upon the line Z Z,Fig. 4. Fig. 6 is a longitudinal vertical section of the same. Fig. 7 isa longitudinal vertical section like Fig. 3, with a modified form ofconstructing and applying my improvement.

In balanced valves of the type shown, when the steam is shut off and thelocomotive is allowed to run downhill by the force of gravity, thewheels drive the steam-pistons, and these act as air-pumps, throwing outthe contents of the steam-chest into the exhaust and creating a partialvacuum in the steam-chest, steamports, and engine-cylinder. This vacuumcontinually drags back upon the piston and prevents the engine fromrunning downhill, or with the steam shut off, at the requiredspeed. Inorder to overcome this difficulty, reliefvalves have been applied invarious places between the exhaustchamber and ports of the valve toconnect the latter with the steamchest; but as all these relief-valveswere necessarily so made as to close themselves when steam was let intothe chest from the boiler they relieved the vacuum, when steam was D isthe steam-chest secured to the top of the cylinder.

Bis the valve-cylinder, in which the balanced valve V moves to and fro.This cylinder B is connected to the engine=cylinder O by steam-ports cc, and has the eXhaustc-hamber E and exit-pipe e for the escape of theexhaust-steam. The steam-ports c c extend entirely around the valve V,and upon the upper side of the latter they have passages c 0 cutentirely through the valve-cylinder B into them. The top of thecylinderis made flat on its upper side and has a raised lip, 0, around eachaperture 0 into the port 0. Over each opening a avalve, o, is fittedsteam-tight upon its lip c. These valves "0 o are connected to eachother and to a central plunger, A, by a cross-bar, a. The centralplunger, A, fits snugly into a corresponding aperture cut through thetop of the valve-cylinder B into the exhaust-chamber E, but so as tomove up and down therein, thus raising the valves v o"- from their seatsor closing them down.

The central plunger, A, is so made as to have the aperture in which itmoves up and down of greater superficial area than that of eitheraperture covered by valves 1) and to be substantially steam-tighttherein, and the limit of its upward movement is such thatit cannot riseout of that aperture, but only moves upward therein the distancerequired to lift valves 12' '0 off their seats and relieve the piston P.

To limit the motion of the plunger A and valves 12 '0', cars 5 5 areformed upon the outer sides of the valves 1; c and screw-bolts 6 6 arepassed loosely through vertical holes in the same and screwed firmlyinto valve-cylinder B. The heads of these bolts arrest the IOD upwardmovement of the valves '0 o and plunger A. Around these bolts lightsprings s 8 may be placed, if desired, to assist in raising the valvesfrom their seats when the steam.

is shut off. The steam-pipe d admits steam to the chest D.

The operation of theinvention is as follows: Suppose steam to be on. Theparts will be in the position shown in Figs. 1, 2, and 3, because thepressure of the steam in chest D upon plunger A over the exhaust holdsthe valves 0 u down upon their sea s 0 c. As soon as steam is shut off,(by a suitable cock attached to inlet d,) the pressureis removed fromplunger A and it will be raised by the action of the piston P, assistedby the springs s s, and lift the valves 0 off their seats, relieving thepiston and preventing their chattering. When steam is again let into thechest D, its pressure upon plunger A will move it downward and close thevalves o 1), because the area of the plunger-opening is larger than thatof opening 0 and the steam rushing into the latter will not overcome theforce exercised by it upon the plunger.

In Figs. 4, 5, and 6 is shown a modification in which the plunger A isattached to the cross-bar a by a pin, of, passing through bar a, andprovided with a spring, 7, between its head and the bar, and the plungerhas a horizontal flange, 8, projecting outwardly around its upper edgeand resting upon a seat upon cylinder B when the plunger is presseddown. This arrangement allows the valves 12 o to be seated independentlyof the plunger A and the latter to be supported independently on flange8 by its subsequent downward movement. The flange can be ground to forma steam-tight joint.

If the plunger A is made to fitsnugly enough in the aperture in the topof the steam-chest in which it works up and down, or if the holes in theears 5 5 are made to fit the bolts 6 6 snugly enough to prevent theplunger and valves from dropping down by gravity, the springs s 8 may beomitted, as the pressure of the steam when on will cause the valves o o"to be closed, and the vacuum in the steamchest will cause them to beopened when the steam is off.

It will be observed that the valves 12 v, although referred toseparately, really constitute one piece of metal or valve covering twoopenings into the valve-cylinder B.

In Fig. 7 another method of applying the relief-valve is shown. In thisconstruction the plunger A is made to enter the discharge end of thesteam-pipe d, being fitted to an en: largement, d of the latter, and therelief-valve a, corresponding to o a in the other construction, fitsdirectly over a passage through cylinder B into the exhaust and isconnected to the plunger by a short spindle, a. This spindle movesfreely through a guide-hole in the yoke b, which is bolted to the top ofcylinder B. The plunger A and relief-valve n are so arranged that whenthe plunger is forced out of the into the chest the valve will enter atubular extension, n around the valve-seat n and the pressure of thesteam upon the top of the valve will continue to withdraw the plunger Afrom the pipe d as the valve is forced downward upon its seat. thusaffording the necessary clearance of the plunger from the steam inletinto the chest. A valve, d, in steam-pipe (2 serves to let on and shutoff the steam. The stem a may be made to fit snugly enough 1n the yoke12 to cause the valvea and plunger to remain up when raised, or thespiral spring a may be placed around the stem between the plunger andyoke b to assist in raising the valve, ifdesired. In any event, when thesteam is shut off the valve will be in the posltlon shown in Fig. 7, andthe letting on ofthe steam automatically closes the valve by itspressure upon the plunger, as in the former construction.Althoughthislatter construction (shown in Fig. 7) is effective, yet Iprefer to have the relief-valve open into the steam-ports c c, becausethe lead of the balanced valve V closes these ports alternately to theexhaust-chamber E, and consequently to the action of the valve 11., fora short space during each stroke, while the valve can never close therelief-passages c c from the ports. There is also an advantage inhavingthe relief-passages c 0 always open when the steam is shut off, becauseif allowed to close by gravity there is a period 1n each stroke of thepiston when a partial vacuum 1s formed in each port 0, which is whollyovercome by the relief-valve v standing open. The part termed theplunger A will be observed to be, in fact, such a plate or surfaceattached to the valve as shall, when presented to the pressure of theinfiowing steam into the chest D, move the valve downward upon its seatfrom the open position in which it is held or sustained while the steamis shut off, and thus allow the steam-pressure to hold the valve shut.This surface or plate attached to the valve may be presented in variousways besides those I have illustrated to the steam-pressure toaccomplish this result without departing from the spirit of myinvention.

With either construction shown, however, the relief-valve only moveswhen steam is shut off or let on, and the wear of the valve and itsconsequent liability to get out of order are in a great measureovercome, and the exhaustchamber Eis connected with the steam-chest D.

What I claim as new and of my invention 1s- 1. The combination of thesteam-chest D,the valve-cylinder B, the valve V, the steam-ports c c,the exhaust-chamber E, and a relief-valve connecting the exhaust chamberwith the steam-chest, arranged to remain open while the steam is shutoff from the chest, and having a plunger or plate connected therewithand adapted to be acted on by the steam-pressure when steam is let onand to close the reliefvalve, substantially as described.

2. The combination of the steam-chest D, the

valve-cylinder B, the valve V, the steam-ports c c, the exhaust-chamberE, and a relief-valve connecting the exhaust chamber with thesteam-chest, arranged to remain open while the steam is shut off fromthe chest, and having a plunger or plate connected therewith by ayielding connection and adapted to be acted on by the steam-pressurewhen it is let on and to close the relief-valve, substantially asdescribed.

3. The combination of the steam-chest D,the valve-cylinder B, the valveV, the steam-ports c c, the exhaust-chamber E, and a relief-valveconnecting the ports 0 c separately with the steam-chest, arranged toremain open while the steam is shut off from the chest, and having aplunger or plate connected therewith and adapted to be acted on by thesteam-pressure when steam is let on and to close the re lief-valve,substantially as described.

4. The combination of the steam-chest D, the valve-cylinder B, the valveV, the steam-ports c c, the exhaust-chamber E, and a relief-valveconnecting the ports a c separately with the steam-chest, arranged toremain open while the steam is shut off from the chest, and having aplunger or plate connected therewith by a yielding connection andadapted to be acted on by the steam-pressure when it is let on and toclose the reliefvalve, substantially as described.

5. The combination of the steam-chest D,the

.in exhaust-chamber E and connected to said relief-valves by yieldingfastenings, substantially as described.

DAVID HALL RICE.

Witnesses:

WILLIAM P. BLAKE, N. P. OCKINGTON.

